Luis ate 2 slices of pizza. Tiffany ate 2 slices. If Luis ate $\dfrac{2}{9}$ of the pizza, what fraction of the pizza was eaten?
Answer: If 2 slices represent $\dfrac{2}{9}$ of the pizza, there must have been a total of 9 slices. $\text{fraction of pizza eaten} = \dfrac{\text{number of slices eaten}}{\text{number of slices total}}$ They ate ${4}$ out of $9$ slices. They ate $\dfrac{4}{9}$ of the pizza.